Brush-holder.



PATENTED AUG.11,1908.

F. c. MITCHELL.

BRUSH HOLDER.

APPLIOATION FILED APR.20, 1906.

INVENTEIR FLEIYD E1- MITCHELL- WITNESSES- UNITED STATES. PATENT OFFICE.

FLOYD O. MITCHELL,

OF S OHENEOTADY, NEW YORK, ASSIGNOR TO GENERAL ELEGTRIG COMPANY, A CORPORATION OF NEW YORK.

BRUSH-HOLDER.

Specification of Letters Patent.

Patented Aug. 11, 1908.

Application fi1ed April 20, 1906. Serial No. 312,920.

To all whom it may concern:

Be it known that I, FLOYD O. MITCHELL, a citizen of the United States, residing at Schenectady, in the county of Schenectady and State of New York, have invented certain new and useful Improvements in Brush- Holders, of which the following is a specification.

My present invention has for its object the production of a brush-holder such as is used in connection with dynamo-electric machin ery which shall be simple, compact, and reliable, comparatively inexpensive to manu facture, and in which the brush tension may be readily adjusted. I

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of my invention, however, and the advantages possessed by it, reference may be had to the accompanying drawings and descriptive matter in which I have illustrated one of the forms in which my invention may be embodied.

Of the drawings, Figure 1 is an elevation of a brush-holder with the cooperating commutator shown diagrammatically; Fig. 2 is an elevation of the brush-holder taken at right angles to Fig. 1 wiLh the brush-holder stud support shown in section; Fig. 3 is a perspective view of a portion of the brushholder and support; Fig. 4 is a perspective view of the brush and a portion of the brushholder not shown in Fig. 3; and Fig. 5 is a perspective view disclosing a modified form of resilient member. 7

Referring to the drawings, 1 represents the brush-holder yoke which is provided with a socket 3 having flat sides in which is secured the brush-holder stud 4. As shown, the brush-holder stud 4 is provided with a collar 5 which abuts against one side of the yoke, and has its end passing through the yoke threaded to receive a clamping nut 6. Suitable insulation 7 may be employed to insulate the stud from the support.

The portion of the stud at the right of the collar 5 in Fig. 3 is cylindrical and has a radially extending kerf or slot 8 formed in it, which may extend partially or entirely through the stud. In the kerf S is secured a resilient member in the form of a plate 9 of spring metal by means of pins 10. The plate 9 which in the form shown forms the tension member for two separately movable brushcarrying or engaging members, is bifurcated, each bifurcation 11 directly cooperating with one brush-carrying member in a manner hereinafter described.

Each brush-carrying member is in the form of a lever member 12 having a centrally located boss or enlarged portion 13 and two arms 14 and 15 extending from opposite sides of the enlarged portion. As shown, the part 13 is formed with a curved seat in which the stud 10 is movably received. This seat does not entirely surround the stud 10 as a portion is cut away at 16 to receive the plate 9. The arm 14 is provided with a threaded socket in which is received a screw 17 having a knurled head 18. The threaded end of the screw 17 bears against the appropriate spring member 11. In the form shown the arm 14 is split into two parts each of which includes a portion of the socket for the screw 17. The diameter of the screw 17 is made slightly greater than the normal diameter of the socket in which it is received. As a result, the screw is spring held in its socket and does not work loose.

The second arm 15 of the member 12 is provided with a socket to receive the brush 19. The brush 19 which may be of any suitable form or style is in the actual construction shown, formed of layers of spring metal such as copper. The brush is held in place by a clamping screw 20. After the members 12 are assembled on the stud 10 they may be secured in place by a nut 21 threaded on the free end of the stud.

With the construct-ion shown, the pressure with which each of the two brushes mounted on a single stud 10 bears against the cooperating commutator 22 may be readily adjusted by manipulating the corresponding screw 17 without disturbing the other brush or without removing either brush from the commutator. By splitting the plate as shown, the effect of independent spring members for each brush-holder is obtained, while the machining and labor of securing in place the single plate used for the two brush-holders is practically no greater than would be necessary for each of two plates if such were employed. To enlarge the range of the resilient member 9, its effective length may be increased by the formation of transverse corrugations 9 in the body of the member, as shown in Fig. 5.

While the construction hereinbefore, described possesses excellent properties, it will be understood by those skilled in the art that changes may be made in the form of my in vention without departing from its spirit, and I do not wish the claims hereinafter made to be limited to the particular construction disclosed more than is made necessary by the state of the art.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. In combination, a brush-holder stud, a resilient member secured directly thereto, a brush engaging member pivotally mounted on the stud, and an adjustable member carried by said brush-carrying member and engaging with said resilient member for varying the angular relation between the resilient member and the brush-carrying member.

2. In combination, a slotted stud, a resilient plate having one edge secured in said slot, a plurality of brush-carrying members pivoted on said stud, and an adjustable eonnection between each of said brush-carrying members and said plate.

3. In combination, a stud having a slot formed in it, a resilient plate having one edge secured in said slot, and a brush-carrying member pivotally mounted on said stud, and engaging said resilient plate.

4. In combination, a stud having a slot formed in it, a plate having one edge secured in said slot, and a brush-carrying member having a tubular boss in which said stud is received, said boss being cut away to clear said. plate.

5. In combination, a stud having a slot formed in it, a plate having one edge secured in said slot, and a brush-carrying member having a socket formed in it in which said stud is loosely received, said member having formed in it a slot, extending radially from said socket and receiving said plate.

6. In a dynamo-electric machine, a brush holder stud, a resilient plate secured thereto, a plurality o'l brush-engaging members pivotally engaging the stud, and an adjustable connection between each brush a carrying member and said plate.

7. In combination, a brush-holder stud having a slot formed in it, a resilient plate having one edge secured in said slot, the edge of said plate remote from the stud being divided into lingers, a plurality of brush-carrying members pivotally mounted on said stud, and an adjustable connection between each brush-carrying member and a "finger of said plate.

8. In combination, a commutator, a brushholder stud, a brush, a member for forcing the brush against the commutator, said member having a curved seat partially but not entirely encircling said stud, a resilient member secured to said stud and extending from the portion of the stud not encircled. by said seat, and a connection between said mem bers.

9. In combination, a commutator, a plurality of brushes, a brush-holder stud, a resilient plate secured thereto, a plurality of" members, one for forcing each brush against the commutator, said members being pivotally connected to said stud, and an adjustable connection between each of said members and said plate.

10. In combination, a brush-holder stud, a slot formed in it, a resilient plate secured in said slot, a brush-engaging member pivotally secured to said stud, and having a slit formed in it, a threaded socket 'lormed partly in each of the portions of the member at opposite sides of said slit, and a screw tension member in said. socket and engaging said resilient blade, the diameter ol. said screw being greater than the normal diameter ol said socket whereby the screw is spring held in position.

In witness whereof, I have hereunto set my hand this 18th day of April, 1906.

FLOYD (J. MI'ICIIELL.

Vitnesses:

BENJAMIN B. HULL, HELEN ORFORD. 

